The 7 L12 Spectrum Analyzer is a dual-width plug-in unit, for the 7000-Series Oscilloscopes . When used with any of these oscilloscopes, it displays a spectrum of signal energy with in any frequency span to 1.8 GHz. The unit contains horizontal sweep and timing circuits, for frequency and time domain displays, and also means by which an external sweep source can be applied to slave the 71_12 to external devices, such as a recorder.